Need help to choose a design for a Qt 5.5 framebuffer app on ARM SBC

Hello,

I am designing an application on an ARM single board computer (SBC) without an X server. I don't use a Linux distribution, I built the system to fit my needs. I'll be using Qt 5.5 and Qwt6.

The thing is that the users of my app are used to remotely logging to computers with VNC, Teamviewer, etc. to control computers, and I'd like to provide them with this functionality, despite the lack of an X server.

So, I can picture 2 options :

client-server application : a daemon running in the background and a front-end talking together over the network. The front-end will run on the SBC and on users's computers.
web server : my Qt app on the device could read/write files to interact with a web server, used to present data to the user (no fancy features needed)

The refresh rate doesn't have to be faster than 1 - 10s. I need to expose a few scalars, and a few time series. The users will set a few properties (boolean, character strings and scalars). Users' computers run on Windows, Mac OSX, and Linux.

I have quite some Qt/Widget programming experience, but not with the network modules nor CGI scripting. Could someone point out the pros and cons of each options, and give me some references ?

Thanks.